<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qstyleplugin.cpp --> <title>QStylePlugin Class | Qt Widgets 5.9</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.9</td><td ><a href="qtwidgets-index.html">Qt Widgets</a></td><td ><a href="qtwidgets-module.html">C++ Classes</a></td><td >QStylePlugin</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"> <div class="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#public-functions">Public Functions</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">QStylePlugin Class</h1> <!-- $$$QStylePlugin-brief --> <p>The <a href="qstyleplugin.html">QStylePlugin</a> class provides an abstract base for custom <a href="qstyle.html">QStyle</a> plugins. <a href="#details">More...</a></p> <!-- @@@QStylePlugin --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <QStylePlugin></span> </td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += widgets</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Inherits:</td><td class="memItemRight bottomAlign"> <a href="../qtcore/qobject.html">QObject</a></td></tr></table></div><ul> <li><a href="qstyleplugin-members.html">List of all members, including inherited members</a></li> </ul> <a name="public-functions"></a> <h2 id="public-functions">Public Functions</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qstyleplugin.html#QStylePlugin">QStylePlugin</a></b>(QObject *<i>parent</i> = Q_NULLPTR)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qstyleplugin.html#dtor.QStylePlugin">~QStylePlugin</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> virtual QStyle *</td><td class="memItemRight bottomAlign"><b><a href="qstyleplugin.html#create">create</a></b>(const QString &<i>key</i>) = 0</td></tr> </table></div> <ul> <li class="fn">32 public functions inherited from <a href="../qtcore/qobject.html#public-functions">QObject</a></li> </ul> <h3>Additional Inherited Members</h3> <ul> <li class="fn">1 property inherited from <a href="../qtcore/qobject.html#properties">QObject</a></li> <li class="fn">1 public slot inherited from <a href="../qtcore/qobject.html#public-slots">QObject</a></li> <li class="fn">2 signals inherited from <a href="../qtcore/qobject.html#signals">QObject</a></li> <li class="fn">1 public variable inherited from <a href="../qtcore/qobject.html#public-variables">QObject</a></li> <li class="fn">10 static public members inherited from <a href="../qtcore/qobject.html#static-public-members">QObject</a></li> <li class="fn">9 protected functions inherited from <a href="../qtcore/qobject.html#protected-functions">QObject</a></li> <li class="fn">2 protected variables inherited from <a href="../qtcore/qobject.html#protected-variables">QObject</a></li> </ul> <a name="details"></a> <!-- $$$QStylePlugin-description --> <div class="descr"> <h2 id="details">Detailed Description</h2> <p>The <a href="qstyleplugin.html">QStylePlugin</a> class provides an abstract base for custom <a href="qstyle.html">QStyle</a> plugins.</p> <p><a href="qstyleplugin.html">QStylePlugin</a> is a simple plugin interface that makes it easy to create custom styles that can be loaded dynamically into applications using the <a href="qstylefactory.html">QStyleFactory</a> class.</p> <p>Writing a style plugin is achieved by subclassing this base class, reimplementing the pure virtual <a href="qstyleplugin.html#create">create</a>() function, and exporting the class using the <a href="../qtcore/qtplugin.html#Q_PLUGIN_METADATA">Q_PLUGIN_METADATA</a>() macro.</p> <pre class="cpp"> <span class="keyword">class</span> MyStylePlugin : <span class="keyword">public</span> <span class="type"><a href="qstyleplugin.html#QStylePlugin">QStylePlugin</a></span> { Q_OBJECT Q_PLUGIN_METADATA(IID <span class="string">"org.qt-project.Qt.QStyleFactoryInterface"</span> FILE <span class="string">"mystyleplugin.json"</span>) <span class="keyword">public</span>: MyStylePlugin(<span class="type"><a href="../qtcore/qobject.html#QObject">QObject</a></span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span>); <span class="type"><a href="qstyle.html">QStyle</a></span> <span class="operator">*</span>create(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&</span>key); }; </pre> <p>The json metadata file <code>mystyleplugin.json</code> for the plugin needs to contain information about the names of the styles the plugins supports as follows:</p> <pre class="cpp"> { "Keys": [ <span class="string">"Rocket"</span>, <span class="string">"Starbuster"</span> ] } </pre> <p>See How to Create Qt Plugins for details.</p> </div> <p><b>See also </b><a href="qstylefactory.html">QStyleFactory</a> and <a href="qstyle.html">QStyle</a>.</p> <!-- @@@QStylePlugin --> <div class="func"> <h2>Member Function Documentation</h2> <!-- $$$QStylePlugin[overload1]$$$QStylePluginQObject* --> <h3 class="fn" id="QStylePlugin"><a name="QStylePlugin"></a>QStylePlugin::<span class="name">QStylePlugin</span>(<span class="type"><a href="../qtcore/qobject.html#QObject">QObject</a></span> *<i>parent</i> = Q_NULLPTR)</h3> <p>Constructs a style plugin with the given <i>parent</i>.</p> <p>Note that this constructor is invoked automatically by the moc generated code that exports the plugin, so there is no need for calling it explicitly.</p> <!-- @@@QStylePlugin --> <!-- $$$~QStylePlugin[overload1]$$$~QStylePlugin --> <h3 class="fn" id="dtor.QStylePlugin"><a name="dtor.QStylePlugin"></a>QStylePlugin::<span class="name">~QStylePlugin</span>()</h3> <p>Destroys the style plugin.</p> <p>Note that Qt destroys a plugin automatically when it is no longer used, so there is no need for calling the destructor explicitly.</p> <!-- @@@~QStylePlugin --> <!-- $$$create[overload1]$$$createconstQString& --> <h3 class="fn" id="create"><a name="create"></a><code>[pure virtual] </code><span class="type"><a href="qstyle.html">QStyle</a></span> *QStylePlugin::<span class="name">create</span>(const <span class="type"><a href="../qtcore/qstring.html">QString</a></span> &<i>key</i>)</h3> <p>Creates and returns a <a href="qstyle.html">QStyle</a> object for the given style <i>key</i>. If a plugin cannot create a style, it should return 0 instead.</p> <p>The style key is usually the class name of the required style. Note that the keys are case insensitive. For example:</p> <pre class="cpp"> <span class="type"><a href="qstyle.html">QStyle</a></span> <span class="operator">*</span>MyStylePlugin<span class="operator">::</span>create(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&</span>key) { <span class="type"><a href="../qtcore/qstring.html">QString</a></span> lcKey <span class="operator">=</span> key<span class="operator">.</span>toLower(); <span class="keyword">if</span> (lcKey <span class="operator">=</span><span class="operator">=</span> <span class="string">"rocket"</span>) { <span class="keyword">return</span> <span class="keyword">new</span> RocketStyle; } <span class="keyword">else</span> <span class="keyword">if</span> (lcKey <span class="operator">=</span><span class="operator">=</span> <span class="string">"starbuster"</span>) { <span class="keyword">return</span> <span class="keyword">new</span> StarBusterStyle; } <span class="keyword">return</span> <span class="number">0</span>; } </pre> <!-- @@@create --> </div> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2017 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>